Method for producing knitted shoe uppers of shrinkable yarn



' D; v. WHiTlNG ETAL 2,641,004 METHOD FOR DUCING KNITTED SHOE UPPEFBSISHRINKABLE YARN ed Dec. ,26, 1950 June 9, 1953 3nnentors DAV/D V.WH/T/A/G JOHN .5 U/VV4/V (Itlomeg ing the same. In any case, the resultsought is a generally conventional soft sock form that has asubstantially whole bottom or sole.

The sock thus produced is made considerably larger in size than the sizeto which the same is to be shrunk, but is not necessarily made in thefull range of sizes in which shoes are made. At present, it iscontemplated that four basic sock sizes will provide uppers which areusable over the complete range of stock shoe sizes. The last [6 overwhich the sock I is shrunk controls the size of the upper that isproduced.

The considerably larger sock is pulled over last l6. However, beforethis is done, an insole I1 is positioned against the bottom of the lastsubstantially as shown. The sock is then adjusted and centered on thelast and the extension portion I3 is pulled, with reasonable tautness,to make the sock conform to the contours of the last. The excess ofmaterial above the last is bunched and tied in the manner suggested inthe drawing. The opening I5 may be spanned by synthetic threads orbunched or gathered in the manner of portion it.

The lasted sock is then subjected to a shrinking step which is suggestedin Fig. 3 wherein a closed receptacle I 8 encloses the sock and retainsthe same for a period of time in an atmosphere of heat. A steam inlet l9supplies dry or wet steam, as desired, to the receptacle and the heatthereof is effective to shrink the sock tightly around the last, thefibers hardening in the process from their initial soft condition to ahard yet elastic condition. Other heating methods may be used, the samebeing chemical reaction, open flame, hot or boiling water, etc. In anycase, the intent is to activate the synthetic fibers to cause them toretract or relax and, thereby, draw the knitted fabric upper tightlyaround the form of the last. The time of the heating step may varyaccording to proportion of the initial size of the sock and the shrunksize and according to the medium employed to effect shrinking. A minuteor so is sufficient when steam is used and the shrinking is moderate.Longer time is used where greater shrinking is involved. By employing aheat medium that is of higher temperature, as between 212 and 250 F.,the fibers set and retain the set form unless subjected to highertemperatures. under normal conditions.

The degree of shrink in any direction may be controlled as desired byknitting a sock in which The latter is unlikely, of course,

inside of the sock or from the outside thereof,

as desired.

After a few minutesfive or ten-or when the lasted sock is cool enough tohandle, the extension portion [3 is removed. As shown in Fig. l, thelast [6 may be provided with a guide groove 20 along which a cuttereffects severance of portion l3 from the ultimate upper II. If desired,the last may terminate along the line of groove 20, in which case, thetop of the last will serve to guide a severing cutter.

The upper thus provided may then be relasted or left on last I6 and theheel and sole 4| is applied in the usual manner by pasting, cementing,or nailing, as the case may be.

The shoe is now complete except for providing a finish for the contouredge of the upper. As shown in Fig. 4, said edge may be seared with aheated tool to fuse the fibers of the yarn along the severance line tocoagulate the same and form a finishing bead 2|. This may be done beforeor after removal of the shoe from the last. Fig. 5 shows anotheredge-finishing method, the same entailin the application of a binding 22by stitching, cementing or pasting the same in place. Sincebinding-applying machines are available, the latter edge-finishing stepcan be effectively accomplished.

As shown in Fig. 2, if open-toed uppers are desired, the sock is knittedwith an open extension 23 at the toe, similar to but smaller thanextension I3. In other respects, the shoe is processed as abovedescribed except that said extension 23 is severed from the upper asguided by a groove 24 provided in the last. The edge thus formed at theupper toe is bound as suggested in Figs. 4 and 5.

Another way of achieving a finished edge along the upper edge of theupper is shown in Figs. 3, 6 and '7. In this case the sock extension l3may be materially reduced in length with the result that considerablematerial is conserved. As shown, the extension 25 is relatively short,being only long enough to enable folding the upper around a tightlyapplied binding cord or tape 26. This is expedited by providing the lastI6 with a downwardly facing shoulder 2! as in Fig.6 or with a groove 28as in Fig. 7, said shoulder or groove, as the case may be, retaining thecord along a desired top line. Now, the slack and soft materlal of thesock may be tucked in behind the cord to form a double fold 29 thatspaces the cord from the last substantially as shown. The body of thesock, being much larger than last [6, is loosely draped thereover asshown in Fig. 3. Of course, the size of the sock, relative to the sizeof the last, is such that the initially slack sock body will shrinktightly over the last, and the size of the opening in upper l I suchthat the same is conformed to groove 28 by cord 26. If desired, tacks 36or other suitable temporary means may be employed to center and alignthe loose sock on the last. The lasted sock is shrunk onto the last ashereinbef ore set forth.

The sock shrinks to the line of the top line as defined by cord 26 andafter the last is removed, it is only a matter of trimming away theextension 25, as along a line 3|, to leave the upper with a properlyfinished top line. In Fig. 6, it will be seen that the finishing beadthus formed does not encroach on the shoe opening. While the bead ofFig. 7 does, the encroachment can be kept small by reducing thethickness of the cord.

From the method above disclosed, it will be seen that the shoe providedhas an upper I l and a substantially complete bottom I2, which areintegrally formed of a knitted fabric. It will be evident that such ashoe will be form-retaining and, thus, will resist deforming. Thethermo-set fabric is stable under all normal conditions, imparting tothe shoe strength desirable in such items. The various knitting methodsenable incorporation of beauty-enhancing designs in the fabric at noadditional cost, a great latitude of employment of open work, etc.,being available to the designer.

Although the present invention has been described with respect tocertain preferred methods, and steps thereof, it' will be realized thatvariations may be practiced without departing from the spirit and scopeof the invention. Accordingly, we desire to reserve to ourselves suchmodifications that may fall within the scope of the appended claims.

Having thus described the invention, what we claim and desire to besecured by Letters Patent is:

l. The method of making a shoe upper which consists in providing aknitted soc}: that has a substantially complete bottom and an upper integral therewith, said bottom and upper being formed of pliable and softsynthetic thermo=setting resin yarn that has the property of shrinkingwhen subjected to heat, mounting the sock on a last that issubstantially smaller than the initial size of the body of the sockupper and bottom, confining the upper portion of said upper along a linearound the upper portion of the last in a manner to leave the portion ofthe sock upper below said line and the sock bottom in slack con dition,applying heat to the sock to cause the slack portions of the same toshrink tightly onto the last below said line of confinement to changethe sock from its initial soft and pliable larger condition to a smallerbut stiffer pliable and References Cited in the file of this patentUNITED STATES PATENTS Number Name Date 1,386,654 Pope W Aug. 9, 19211,910,251 Joha May 23, 1938 2,007,262 Tetlow July 9, 1935 2,314,098McDonald Mar. 6, 1943 2,335,210 Guinzburg Nov. 23, 1943 2,435,797 Reed-1 Feb. 10, 1943 2,440,393 Clark Apr. 27, 1948 2,457,630 Beetson Dec.28, 1940 FOREIGN PATENTS Number Country Date 12,786 Great Britain Nov.26, 1908

